Starfish or sea stars are echinoderms belonging to the class Asteroidea. The names "starfish" and "sea star" essentially refer to members of this class.Starfish are among the most familiar of marine invertebrates. They typically have a central disc and five arms, though some species have more than this. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface. They are opportunistic feeders and are mostly predators. They have complex life cycles and can reproduce both sexually and asexually. Most can regenerate damaged parts or lost arms and they can shed arms as a means of defence. While a starfish lacks a centralized brain, it has a complex nervous system.
|Photo credit: © Chris Campbell|
|Huge starfish on Case inlet beach - LINK|
|Vancouver Island, British Columbia, Canada - LINK|
|Starfish at Budleigh Salterton. Photo credit: Scott Eley - LINK|
|Photo credit: © Liz Edgar|